The Depths. The sinking, half forgotten remains of the above. Still living history, warped and maddened.

The Underlands. A mirror civilization, a twisted shadow of our own world. Thick, sweet air. Strange white trees. Damp, living earth. And a haunting song…

The Underworld, and Hell. Both of these are real, physical places. Hell is where demons live. They are exile cosmic creatures, warped by their exposure to our world. The underworld is where the dead go. You might meet them there.

The Abyss. The absolute border to nothingness. A place where reality is weaker than the mind. Where the fallen demons live. Where the broken souls remain.

“Below” the Abyss lies only void, and the Other. Directions don’t really work there, as the place probably has more dimensions than strictly neccessary. Going there would most likely result in instant anihilation.

Adventurers go into the dungeon and kill the hostile cells that are the monsters. As they venture deeper, they themself start to change and grow (gaining levels). Maybe (some) monsters are adventurers that lost themselves?

This could also justify the xp for gp rule in a fun way. Treasure in dungeons is loaded with the touch of the Other (potential energy). When its brought to the surface that potential energy must go somewhere: the carrier. The delvers who come back are filled with power, and in time become superhuman (or inhuman).

This is turning into something like Dark Souls / Bloodborne. Again. Heh. Well, I don’t mind some Souls in my D&D, but I’ll just end this post for now…